External and internal quality traits of eggs from different ornamental chicken breeds.

This study analyzed the internal and external quality traits of eggs derived from hens of different breeds, including Silkie, Sultan, Cochin Bantam, Brahma and White Leghorn. The highest mean weight was noted for eggs originating from the White Leghorns breed, and the lowest was for eggs from the Cochin Bantams. Simultaneously, both a positive correlation between the egg weight and the percentage of albumen (r = 0.876) and a negative correlation between egg weight and the percentage of yolk (r = - 0.842) were found. The eggshell composition varied significantly in mean phosphorus amount, whereas the calcium content did not differ significantly. Despite this, eggshell strength varied significantly between breeds. Regarding cholesterol and fatty acid levels, the highest amount of cholesterol was noted in the Cochin Bantam breed, and the lowest was in the White Leghorn, although Leghorn was the breed characterized by the highest saturated fatty acid levels, and Cochin Bantam was the lowest. Regarding the polyunsaturated fatty acids (which have been proven to positively influence the cardiovascular system), the highest levels were obtained by Leghorn eggs, and the lowest were obtained by Silkie eggs. In conclusion, the study indicates that ornamental chicken breeds are a source of high-quality products, which could be attractive to consumers, additionally supporting traditional farming and animal genetic resources.

Isolation and molecular typing of Mycobacterium avium subsp. paratuberculosis from faeces of dairy cows.

Mycobacterium avium subsp. paratuberculosis (MAP) is the cause of paratuberculosis mainly in domestic and wild ruminants; paratuberculosis is also known as Johne's disease. This disease is endemic all over the world generating significant economic losses, especially in dairy herds, although, MAP is the cause of infection in many other species including primates. Currently, MAP mycobacteria are recognized as pathogens transmitted by food. They are a potential threat to animal and human health. Infected animals excreting mycobacteria with faeces are the main source of MAP. The development of control strategies and disease control are based on determination of the genetic diversity of the MAP strains causing Johne's disease. This study describes 43 strains isolated from a herd of dairy cows located in northern Poland. The types of MAP were determinted based on the polymorphism analysis of two insertion fragments: IS900 and IS1311. The polymorphism of IS900 was analyzed with the use of a PCR multiplex according to Collins' method and the IS1311 polymorphism with the use of the PCR-REA method. Based on the differences observed, the strains isolated were classified into two MAP types, cattle (C-type) and sheep (S-type), with the predominance of the cattle type.

Determination of the cytotoxic activity of Campylobacter strains isolated from bovine and swine carcasses in north-eastern Poland.

The study was carried out to determine the cytotoxin production by Campylobacter spp. isolated from slaughtered cattle and swine in north-eastern Poland. In total three commercial slaughterhouses were sampled during one year. Carcass swabs were taken to detect the level of Campylobacter spp. contamination. Campylobacter spp. was found in 50 (34%) out of 147 swine carcasses examined. PCR analysis revealed 4 (8%) isolates to be C. jejuni, and 46 (92%) to be C. coli. From a total of 373 bovine carcasses, Campylobacter spp. were isolated from 49 (13.1%) samples. The results regarding the occurrence of cdt genes associated with cytotoxicity indicated that 100% of C. jejuni and 67.4% C. coli obtained from pigs had all three cdtA, cdtB and cdtC genes. In case of C. jejuni strains isolated from cattle all cdt genes were confirmed in 93.9% isolates. The isolates possessesing all cdt genes had higher cytotoxic activity against cell lines used. The isolates both from cattle and swine were characterized by the highest cytotoxicity against HeLa cells. The values obtained reached 80.8% for C. jejuni isolates from cattle and 76.2% for C. jejuni and 69.0% for C. coli isolates from swine. High prevalence of cytotoxicity in Campylobacter spp. indicates a significant epidemiological role of this pathogen in human infections.

Prevalence and antimicrobial resistance of Campylobacter in raw milk in the selected areas of Poland.

During the recent years, an immense increase in the number of food poisoning cases in people caused by Campylobacter (C.) species has occurred. Raw milk, next to poultry meat, is considered the most frequent cause of food poisoning in people caused by the subject bacteria, although it is not always possible to isolate Campylobacter cells from the incriminated milk. Most probably this difficulty is caused by low concentration of the pathogen in milk at the level of 2/3 cells/ml although even such low concentration represents risk to human health. The present study was aimed at determining the occurence of Campylobacter bacteria in milk originating from selected regions of Poland. The isolation method applied in this work was effective in recovering as few as 0.1 cell of Campylobacter per g of food. Among 150 bulk milk samples tested, Campylobacter spp. was isolated from 7 (4.6%) ones. The biochemical identification of the isolated strains conducted by means of conventional biochemical tests as well as by applying the API - Campy tests revealed that all the isolates belonged to the C. jejuni species. Determination of resistance to antibiotics was performed by means of the diffusion disks method for the following antibiotics: gentamicin, ciprofloxacin, ampicillin, chloramphenicol, erythromycin, doxycyclin and tetracycline. Among 7 isolates tested, all were susceptible to ampicillin, chloramphenicol, erythromycin and gentamicin, 28.5% to doxycyclin and 14.2% to tetracycline and ciprofloxacin.

Contamination of turkey carcasses by thermotolerant species of Campylobacter during postslaughter processing.

Ample literature data indicate explicitly that the major source of alimentary infections induced by Campylobacter spp. is poultry meat and its products. The undertaken research was aimed at determining the level of contamination of turkey carcasses during selected stages of postslaughter processing. Analyses were conducted on 200 turkey carcasses that were examined in 10 experimental series. In each series, 5 carcasses were analyzed at the selected stages of processing, i.e.: after defeathering, evisceration, washing and chilling. Swabs were collected from each carcass from 20 cm2 skin surface at the area of neck, steak and wall of the body cavity. Out of 550 samples of swabs from the skin surface and wall of the body cavity, 385 isolates were classified as Campylobacter--positive, which constituted 70% of the samples. Out of 100 analyzed swabs collected from the carcasses after defeathering, 73 (73%) were found to contain Campylobacter species. In turn, the presence of this pathogen was confirmed in 122 (81.33%) out of 150 swabs collected from carcasses after evisceration, in 106 (70.66%) swabs collected after washing and in 84 (56%) swabs collected after chilling.

Campylobacter spp.--a significant microbiological hazard in food. II. Lesions and infection development, pathogenic mechanisms and complications.

Infections with Campylobacter spp. occur as a result of consumption of live cells with food. In developing countries those infections are immensely common, particularly during early childhood and 5 to 10 cases can appear during the initial two years of life. The symptoms appear usually after 1-7 days from infection depending on the number of ingested cells and individual sensitivity. Characteristic symptoms of infections caused by Campylobacter spp. infrequently occurring jointly in the clinical form of the disease include: diarrhea, abdominal pain and increased temperature. In the majority of cases the disease is mild and lasts from 2 to 7 days. Usually Campylobacter are excreted with feces during a period of 7-21 days, sometimes even longer. Occasionally in the increased risk group dangerous complications may occur. They include: bacteremia, meningo-myelitis, neurological disturbances and reactive arthritis.

Campylobacter spp.--a significant microbiological hazard in food. I. Characteristics of Campylobacter species, infection source, epidemiology.

Campylobacter spp. is one of the main etiological factors of gastrointestinal diseases in people manifesting as alimentary infections. The microorganism is isolated 3-4 times more frequently in case of alimentary infections that other enteropathogenes, i.e. Salmonella or E. coli. Campylobacter spp. is a component of ordinary intestinal microflora in many animal species, including slaughter animals. Birds are one of the most important reservoirs of Campylobacter spp. With a relatively high internal body temperature at around 42 degrees C, they are the appropriate environment for those bacteria, which show special thermal requirements. Wide presence of Campylobacter spp. in animal population causes the risk of contamination of food products such as raw meat and milk as well as water.

Biological and chemical hazards occurring in fish and fishery products.

It is common knowledge that fish are a nutritious component of a human diet, as they constitute a valuable and desired source of protein and polyunsaturated fatty acids. However, they are likely to pose a risk to consumer health. The presence of pathogenic bacteria or their toxins, parasites, biogenic amines and toxins or chemical residues may be a causal agent of foodborne illnesses in humans, sometimes even with fatal effect. Usually, infections are a result of insufficient thermal treatment or consumption of raw fish dishes. There are also risk factors that cannot be eliminated by such treatments as cooking, salting or freezing.